Before he had time to answer, Merlini came from the darkroom and captured our attention with what he carried. He had two pint-sized chemist’s bottles and a drinking glass half filled with what, under other circumstances, I would have dismissed as water. There was a saucer lying across its top, bottom up. Of the bottles, one was clear glass with a label bearing in heavy red letters the word: POISON, and, in a smaller size the symbol NaCy and the two words, Sodium Cyanide. The glass of the other bottle was a brownish color and, though half-filled with a heavy crystalline substance, had no label at all.
“Someone around here has been doing some amateur detecting,” Merlini said. He put the glass down on the ping-pong table and turned it slowly. On one side we saw a dark smudge of whorls and lines that was a fingerprint. On the opposite side there were four more, arranged vertically down the glass. The cyanide bottle, too, showed prints, many of them. The other bottle had none.
“Thumb and four fingers,” Merlini said indicating the glass. “Smallish. Probably a woman’s.”
Gavigan put his nose down close. “The powdered graphite.”
“Yes. Our amateur sleuth, whoever he is, used it as an impromptu homemade fingerprint powder and with success. Had you noticed that there was a vacuum water carafe in Linda’s room and no glass?”
“Of course,” Gavigan retorted, “I’m not blind.” He turned to Dr. Hesse. “Can you test this for cyanide at once?”
Hesse came forward, nodding. “You’re lucky this time. Knowing it was cyanide, I brought the reagents for the Prussian Blue test with me. Would you have my bag brought down, Captain?” He lifted the glass carefully, thumb on the top edge, forefinger on tile bottom, and took it into the darkroom.
Malloy jerked an upward thumb at Quinn; and, as the latter started up, Gavigan called, “Send Brady down here too, and bring Arnold. I’m going to—”
“Just a minute!” It was Gail’s voice, sharp, insistent. “Before you get him, I’ve got something to say.”
“Well?”
“It’s about motive.” Dr. Gail returned the Inspector’s stare coolly, but his finger tapped nervously on his cigarette, sending flakes of ash to the floor. “Linda was a selfish, pigheaded spinster fury. As a psychiatric study she was a honey; as a person to live with or around I imagine she was holy hell. She also controlled the lion’s share of a fortune which one or two other persons might naturally feel they should have shared. There’s plenty of motive there, and yet—”
“And yet what?” Gavigan’s voice was sub-zero.
Gail frowned at his cigarette, dropped it on the floor and stepped on it. “There’s a better motive than those,” he said somberly, “a much better motive. If anyone ever had a good and sufficient reason for murder—” He threw a quick look at Merlini. “You asked me about Arnold’s face. I’ll tell you now.”
“I thought you knew,” Gavigan said.
“Yes. But I couldn’t say so until I was sure it had something to do with Linda’s death. Arnold wears make-up all the time, not only on his face, but even on the backs of his hands. There’s a proprietary make-up on the market called Coverfault, which may be what he uses. It’s designed for hiding small discolorations and blemishes of the skin, but Arnold uses it over his whole visible skin surface. I saw him without it once — though he doesn’t know that. I caught him in swimming early one morning — in trunks alone.”
“Well?” Gavigan growled impatiently.
“His body is blue.”
“Blue!” The Inspector didn’t care for the idea at all. His quick eyes scrutinized Gail’s face suspiciously.
I began to think the Doctor might have something there. His theory would explain the dirty streaks I had glimpsed on Arnold’s face the night before — streaks the rain had made in his make-up.
“So that’s it!” Merlini said with some surprise. “Moor’s skin, Doctor?”
“Yes. Argyria. How did you know?”
“I’ve known a few Blue Men. But isn’t Arnold a bit young? I thought they’d mostly died off by now.”
Gail nodded. “They have. That’s just it. How do you suppose he comes to have it?”
Gavigan wanted attention. He slapped his hand flat on the table. “Wait a minute! Go on, Quinn, get Brady and Hesse’s bag.” He eyed Merlini and Gail belligerently. “Now, what are you two talking about? Will someone please exp—”
Merlini obliged. “The Blue Men I knew, Inspector, were circus freaks. Forty years or so ago the medical profession prescribed silver nitrate for stomach ulcers. I don’t know if it cured them, but the medicos were startled when some of their patients started to turn blue — especially when the patients stayed that way — permanently. There wasn’t any cure. Some of them went into side shows. And one that I knew — billed as The Great What-Is-It From Mars—used to dose himself with the stuff to increase the color. He figured as long as he was blue and no hope for it, he might as well be good and blue, and try for a raise in pay.”
“But—” Gavigan began to object.
“The same thing,” Gail said, adding to Merlini’s information, “happened in the early 19th century and again around 1850, when silver salts were prescribed for epilepsy and tabes. It created a whole generation of blue men and women. It’s a slaty, dark, bluish-gray discoloration caused by the tendency of the silver salt to deposit itself in finely divided metallic form in the skin. Silver, of course, turns dark on exposure to light — the reason for its photographic use. And the pigmentation of the skin appears first in the parts exposed to light and particularly the conjunctivae and mucus membranes. You’ve noticed that Arnold barely opens his mouth when he speaks? That’s because the inside of his mouth and his tongue are blue. Even his internal organs—”
“But—” Gavigan got his objection on record this time—“silver nitrate is poisonous taken internally.”
“Sure,” Gail agreed, “it’s a violent corrosive poison if given in a sufficient dose, but that’s 30 grains or more. Minute quantities are neither toxic nor appreciably injurious to the general health. But, when given over an extended period of time, they produce the intense discoloration that Arnold tries to conceal.”
“And you said you were hunting for cyanide when I walked in on you in the darkroom. What were you doing with the silver-nitrate bottle?”
“You mean the bottle with the silver-nitrate label, Inspector. With this bee buzzing in my bonnet, I decided to check up. I discovered that Arnold’s silver-nitrate bottle contains salts all right, salts that look superficially like AgN03 but not silver salts. Merely common sodium chloride — in the rock salt form. It’s not only not silver nitrate, but one of its antidotes.”
Gail turned and picked up the brown bottle that had no label. He removed the glass stopper and tilted perhaps a teaspoonful of the crystals the bottle contained out onto the table. He took one smallish one and touched it lightly to his tongue.
“Bitter, metallic taste,” he said. “That’s silver nitrate.”
Brady came in with Quinn. Gavigan addressed the former, “Finish with that letter?”
Brady nodded. “Couple of faint smudges on the note paper and lots of good ones on the envelope. Postal clerks and mailmen probably. But if you think the letter prints might not be Floyd’s I’ll shoot it to the lab. I can’t bring out a lot of detail with the powder but the silver nitrate bath might do it.”
“Now that,” Merlini commented smilingly, “is what I call a useful chemical to have on hand. Regular little Jim Dandy jack-of-all-trades. Sail right in, Brady. The silver nitrate’s there in front of you.”
“Well,” Brady said, “it’s not as simple as that. I’d need—”